In recent years, various vehicles equipped with a rear wheel toe angle control device have been developed for the purpose of enabling the vehicle to quickly change the heading thereof and improving the driving stability of the vehicle by appropriately varying the rear wheel toe angle. According to a known rear wheel toe angle control device, a linear electric actuator including an electric motor and a feed screw mechanism is connected between the knuckle of each rear wheel suspension and the vehicle body so that the toe angles of the rear wheels may be individually varied by extending and retracting the electric actuators. See Patent documents 1 and 2, for instance.
The fuel mileage of a vehicle decreases with the increase in the rolling resistance of the wheels. The rolling resistance depends on the tread pattern and the material of the tire, but is known to significantly increase when the wheel alignment including the toe angle deviates from a proper setting. Therefore, the wheel alignment is properly set before the vehicle leaves the manufacturing plant.